Abstract

Inheritance of Precocity and of Agronomic Characters in Soybean

Author(s): F.G. Teixeira, O.T. Hamawaki, A.P.O. Nogueira, R.L. Hamawaki, C.L. Hamawaki, T.P. Mattos, I.C. Silveira and L.A. Medeiros

Precocious soybean cultivars enable crop rotation and low pressure to the biotic and abiotic factors. This study aimed to determinate the inheritance of characters related to precocity and agronomic characters in soybean segregating population, coming from contrasting genitors to cycle. The experiment was conducted at a greenhouse located at Capim Branco farm, belonging to Federal University of Uberlândia. The MG/BR 46 Conquista and UFUS 6901 cultivars were used to bi-parental crossing and acquirement of F1 and F2 populations. The individuals of the genitors, F1 and F2 populations were evaluated to eight characters and the phenotypic, genetic and environmental variances, broad-sense heritability, average degree of dominance and gene number were determined. The average for number of days for flowering and number of days to maturity in the F1 generation was 40.26 and 103.52 days and in the F2 generation was 37.85 and 105.88 days, respectively, which fits into the classification of semi-precocious. The heritability varied from 2.36% for number of grains per pod – controlled by 160 genes, to 85.39% for number of days for maturing – controlled by two genes. On the F2 population, the existence of transgressed segregates was found, except for number of days to maturity, number of nodes and intersection height of the first pod. It was concluded that the genetic variance and heritability of the agronomic characters of the F2 population, allows the acquirement of selection of superior individuals in terms of precocity, height, number of nodes and compounds of productivity, being promising genotypes in the soybean breeding program

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